Selective Synthesis of Functionalised Linear Aliphatic Primary Amines Using Photoredox Catalysis

Abstract

Linear aliphatic primary amines are crucial and every year, at least, millions of tonnes are required to meet this demand. Therefore, significant interest has been shown in finding new chemical routes for the synthesis of aliphatic primary amines. However, to comply with the sustainability requirements, synthetic routes using inexpensive feedstocks are highly prioritized. In this regard, the hydroaminoalkylation (HAA) reaction, i.e. functionalization of an olefin with an aminoalkyl group and a hydrogen atom across the C=C double bond, is desirable due to the wide availability and lower price of olefins. Although photoredox catalysis is already known to synthesize amines, the synthesis of linear aliphatic amines is only limited to hydroaminomethylation (HAM) reactions i.e. functionalization of an olefin with an aminomethyl group and has never been applied to the synthesis of long chain linear aliphatic primary amines. Considering this, the synthesis of functionalized linear aliphatic primary amines is demonstrated by using a novel photoredox-mediated decarboxylative hydroaminoalkylation reaction, which exhibited a wide scope with excellent yields. The strength of this method is demonstrated by drug synthesis, late-stage modifications of complex pharmaceuticals and elaborated with detailed mechanistic studies.